A legal limit on driving hours isn’t the same as a finding that a driver was alert enough to operate a commercial truck safely. Fatigue can set in before a log shows an Hours of Service violation, and a compliant-looking log doesn’t reveal whether the driver had restorative sleep, worked off the clock, or faced pressure to keep moving.
When Federal Hours of Service Rules Govern Arizona Trips
The first question is whether federal regulations govern the trip. The Federal Motor Carrier Safety Administration regulates interstate commercial motor vehicle operations, including trucks involved in commerce across state lines.
Hours of Service rules limit a driver’s work and driving schedule. They generally apply to property-carrying commercial vehicles in interstate commerce. An Arizona-only route requires analysis under applicable intrastate requirements, and the federal interstate limits shouldn’t be assumed to govern.
Federal rules also place duties on the company operating the truck. A carrier can’t require or permit a driver to violate applicable Hours of Service limits, even when more than one carrier uses that driver’s services. That distinction matters when a delivery deadline, dispatch instruction, or company practice contributed to unsafe driving.
Federal Driving, Duty & Rest Limits
For many property-carrying drivers subject to federal rules, the following limits provide a useful starting point after a collision:
- 11-Hour Driving Limit: A driver may drive up to 11 hours only after taking 10 consecutive hours off duty.
- 14-Hour Duty Window: A driver may not drive after the 14th consecutive hour after coming on duty, even without reaching 11 hours behind the wheel.
- 30-Minute Break: A driver must take a qualifying 30-minute break after eight cumulative hours of driving since the end of the last qualifying break.
- Weekly Limits: Drivers generally may not drive after 60 on-duty hours in seven consecutive days or 70 on-duty hours in eight consecutive days for carriers that operate every day.
The 14-hour duty window runs continuously. On-duty work includes inspecting or servicing the truck, loading or unloading cargo, waiting for dispatch, fueling, and completing paperwork, even when the truck isn’t moving.
A driver who takes at least 34 consecutive hours off duty can use a 34-hour restart to reset the weekly calculation. These limits provide context, but an investigation must compare the records with what happened before the collision.
Logged Hours Don’t Resolve Fatigue
Fatigue is a safety issue in its own right, not merely a math problem on a logbook. Federal regulation prohibits a commercial driver from operating when fatigue impairs alertness. It also prohibits a trucking company from requiring or allowing that operation.
The Federal Motor Carrier Safety Administration’s Large Truck Crash Causation Study identified driver fatigue as a factor in 13 percent of serious crashes involving commercial motor vehicle drivers. The agency also reports that research has compared being awake for 18 hours with a 0.08 percent blood alcohol concentration in terms of crash risk.
Those findings don’t establish what happened in a particular collision. They show why an investigation shouldn’t stop with the 11-hour driving limit. Sleep quality, overnight schedules, and work performed outside recorded duty time can also affect alertness.
Records That Reveal Fatigue or Company Pressure
Electronic logs are most useful when compared with other evidence. For most commercial drivers, an electronic logging device automatically records driving time, duty status, and rest periods. The system must also retain information showing edits to recorded data.
A log is only one part of the timeline. Dispatch instructions and location data can show whether the driver was directed to meet an unrealistic delivery time. Maintenance files can reveal whether mechanical problems contributed to the collision or forced the driver to spend additional hours dealing with the truck.
Records worth preserving after a suspected fatigue-related collision include:
- Electronic logging device data and edits to duty-status records.
- Dispatch messages, delivery schedules, and communications with the carrier.
- GPS, toll, fuel, and inspection records that help confirm the truck’s movements.
- Driver qualification, training, and prior safety records when relevant.
- Police reports, crash photographs, witness information, and vehicle damage documentation.
Together, these materials can show whether the recorded schedule matches the trip’s timeline and whether company policies played a role. They can also point to other responsible parties, including a cargo loader, mechanic, vehicle manufacturer, or parts manufacturer.
Steps to Take After a Suspected Fatigue-Related Collision
Your health comes first. Seek medical care and follow treatment instructions. Keep discharge papers, bills, and work restrictions, and save communications from insurers. Photograph the vehicles and road conditions. Also document injuries and visible cargo issues before those details change.
Keep the documents you receive after the collision, including crash report information, insurance correspondence, and witness contact details. Trucking companies and insurers often have access to company-controlled electronic records soon afterward, so preserving information early matters.
Hours of Service records can identify scheduling problems, but they don’t automatically prove fault. A complete review should consider the driver’s conduct, the company’s scheduling and supervision, and road and vehicle conditions alongside the available records.
In Arizona, a truck accident lawsuit generally must be filed within two years of the crash date. Involvement by a government entity can trigger a shorter notice period, so waiting to investigate can affect both the evidence and available legal options.
Preserving electronic records and crash details promptly gives a fatigue investigation a stronger foundation before information becomes harder to obtain. IBF Law Group evaluates driver and carrier liability after a Phoenix truck crash and offers free consultations, virtual consultations, and multilingual support to people in Phoenix and Maricopa County. To discuss the available records and legal options, call IBF Law Group at (602) 833-1110.